Reduction of gastrointestinal tract colonisation by campylobacter

ABSTRACT

Campylobacter are the commonest reported bacterial causes of gastroenteritis in the UK and industrialized worlds. This invention relates to a method of preventing or reducing the colonisation of the gastrointestinal tract of an animal with Campylobacter. Accordingly, the present invention provides a method for disinfection of an animal comprising administering to said animal at least one compound that binds to MOMP or FlaA of Campylobacter in an effective amount to reduce the number of Campylobacter present in the gastrointestinal tract of said animal. The present invention also provides a method of preventing or reducing transmission of Campylobacter from one animal to another.

This invention relates to a method of preventing or reducing the colonisation of the gastrointestinal tract of an animal with Campylobacter. In particular, it relates to reduction or prevention of colonisation of the gastrointestinal tract of poultry with Campylobacter. It also relates to uses of compounds that bind to adhesins on the surface of Campylobacter to prevent the bacteria from adhering to the wall of the gastrointestinal tract of animals and to treat Campylobacter infection in humans and animals.

Campylobacter are the commonest reported bacterial causes of gastroenteritis in the UK and industrialized world. Campylobacter jejuni (C. jejuni) is responsible for about 90% of Campylobacter infections, the majority of the remainder being caused by C. coli. Campylobacter form part of the natural gastrointestinal flora of many birds and domestic animals, but chickens are thought to constitute the largest source of human infection. Infected chickens are asymptomatic despite harbouring up to 10⁸ colony forming units (cfu) per gram of intestinal content. Meat, in particular chicken meat, is often contaminated with intestinal contents including Campylobacter during slaughter. In humans, Campylobacter species cause diseases that vary in severity from mild watery diarrhoea to bloody dysentery. In a small subgroup of patients, the acute phase disease is followed by serious sequelae, including Guillain-Barré syndrome and reactive arthritis.

It is therefore of great interest to provide methods for reducing and preventing the risk of contamination of meat with Campylobacter and therefore the risk of human infection with Campylobacter. It is also of interest to provide new treatments for human infection with Campylobacter (campylobacteriosis).

Accordingly, the present invention provides a method for disinfection of an animal comprising administering to said animal at least one compound that binds to MOMP or FlaA of Campylobacter in an effective amount to reduce the number of Campylobacter present in the gastrointestinal tract of said animal.

The present invention also provides a method for disinfection of an animal comprising administering to said animal at least one compound that binds to MOMP or FlaA of Campylobacter in an effective amount to prevent said Campylobacter from forming a biofilm in the gastrointestinal tract of said animal or to reduce the amount of biofilm formed by Campylobacter in the intestinal tract of said animal.

The present invention also provides a method for preventing or reducing transmission of Campylobacter infection from one animal to another, for example preventing or reducing spread of Campylobacter infection within a flock or herd of animals, for example preventing spread of Campylobacter infection within a flock of chickens; said method comprising administering to said animals, for example said herd or flock of animals, for example said flock of chickens, at least one compound that binds to MOMP or FlaA of Campylobacter in an effective amount to prevent said Campylobacter from forming a biofilm in the gastrointestinal tract of said animal or to reduce the amount of biofilm formed by Campylobacter in the intestinal tract of said animal.

The methods of the present invention may allow disinfection, prevention of biofilm formation and reduction of transmission of Campylobacter between animals by preventing or reducing adherence of Campylobacter of the gastrointestinal tract of said animals. This is advantageous because the fewer Campylobacter that are in the gastrointestinal tract of an animal at the time of slaughter, the lower the risk of contamination of meat from the animal with Campylobacter. The fewer Campylobacter that are in the gastrointestinal tract of an animal the lower the chance of the Campylobacter forming a biofilm in the gastrointestinal tract of the animal. The fewer Campylobacter that are in the gastrointestinal tract of an animal, the lower the chance that the Campylobacter will spread from one animal to another, for example within a herd or flock of animals.

Method of the present invention may be used to reduce the amount of colonisation of the gastrointestinal tract of any animal with Campylobacter. It is particularly advantageous to provide the compounds to animals that will be slaughtered for human consumption, such as, for example, cattle, sheep, pigs, goats, deer, fish, shellfish and poultry. Poultry includes birds that are used for human consumption such as chickens, geese, turkeys and ducks. It is particularly advantageous to use the compounds of the present invention to reduce or prevent colonisation of the gastrointestinal tract of poultry, in particular chickens, with Campylobacter because chickens are a leading source of human infection with Campylobacter.

Campylobacter are gram negative, spiral rod shaped bacteria with a single flagellum at one or both poles. They belong to the epsilon proteobacteria class and are closely related to Helicobacter and Wolinella. Although these species are related they have very different culture requirements and different hosts. Campylobacter species usually live in the gut of animals, in particular chickens while Helicobacter lives in the stomach of humans. Although fastidious in their culture requirements, Campylobacter species, particularly C. jejuni and C. coli, are important human pathogens, causing gastroenteritis of varying severity. Under normal circumstances gastroenteritis is self-limiting, but sequelae associated with campylobacteriosis such as Guillain-Barre syndrome are potentially life threatening. There are many different reservoirs for Campylobacter but the most significant is contaminated meat, particularly poultry.

The number of Campylobacter in the gastrointestinal tracts of animals may be reduced by the methods of the present invention. In one embodiment the number of colony forming units (cfu) of Campylobacter in the gastrointestinal tract of an animal treated with the compounds of the present invention may be reduced by 50%, by 60%, by 70%, by 80%, by 90% or by 100%. In one embodiment Campylobacter may be substantially eradicated from the gastrointestinal tract of animals treated by the method of the present invention.

10000 cfu of Campylobacter are enough for successful chicken colonization. 1000 cfu of Campylobacter are enough to infect a human and cause disease in a human. Therefore, an effective amount of a compound of the present invention is enough of the compound to reduce the number of Campylobacter in the gastrointestinal tract of an animal to a number that is unlikely to cause infection in humans. The number of cfu of Campylobacter that would be ingested by a human if they ate meat from an infected animal may be related to the number of Campylobacter in the gastrointestinal tract of the animal at the time of slaughter but also depends on other factors such as the amount of contamination of the meat with the contents of the gastrointestinal tract of the animal at the time of slaughter.

An effective amount of the compound of the present invention is enough of the compound to prevent colonisation of the gastrointestinal tract of the animal with Campylobacter.

In one embodiment the compounds of the present invention may make Campylobacter less virulent and less capable of infecting humans even if the total number of Campylobacter in the gastrointestinal tract does not decrease. In this embodiment administering a compound of the present invention to an animal may affect the metabolism of Campylobacter and make them less adaptive to environment so that they can not colonize the gastrointestinal tract and are less likely to be transmitted the other animals or to humans.

An effective amount of a compound provided to an animal should be enough to provide the required degree of reduction of Campylobacter colonisation. This may depend on the type of compound and/or the size of the animal. In one embodiment an effective amount of the compound may be 0.3 to 32 mg/day/kg bodyweight of the animal.

The method of the present invention preferably reduces colonisation of the gastrointestinal tract with Campylobacter species, for example Campylobacter jejuni or Campylobacter Coli.

This is advantageous because Campylobacter jejuni is the commonest reported bacterial cause of gastroenteritis in the UK and industrialized world. Campylobacter jejuni (C. jejuni) is responsible for about 90% of Campylobacter infections, the majority of the remainder being caused by C. coli. Campylobacter form part of the natural gastrointestinal flora of many birds and domestic animals and there is therefore a high risk of contamination of the carcasses of these animals when they are slaughtered.

The compound used in the method of the present invention is preferably a compound that blocks the interaction of MOMP or FlaA on the surface of Campylobacter with the cells of gastrointestinal tract. Preferably the compound binds to MOMP or FlaA and competitively or non-competitively inhibits the binding of MOMP or FlaA on the Campylobacter with the cells of the gastrointestinal tract. Preferably the compound used in the present invention may bind to MOMP on the surface of Campylobacter jejuni. Preferably the compound used in the method of the present invention specifically binds to at least one of amino acid residues Arg³⁵², Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ Ile³³⁷, Arg³⁸¹, Asp²⁶¹ and Ser³⁹⁷ of MOMP. In another embodiment the compound of the present invention reduces the interaction between at least one of amino acid residues Arg³⁵², Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ Ile³³⁷, Arg³⁸¹, Asp²⁶¹ and Ser³⁹⁷ of MOMP and the gastrointestinal tract of an animal.

In one embodiment the compound used in the method of the present invention may be natural human histo-blood group antigen or a synthetic human-histo blood group antigen.

Natural human histo blood group antigens are sugars that occur naturally on red blood cells of humans. They are also expressed on the surface of epithelial cells, such as the cells lining the gastrointestinal tract and can be secreted in body fluids such as saliva and breast milk.

The common human histo blood group antigens (BgAgs) consist of a complex and polymorphic group of carbohydrates expressed on the surface layer of erythrocytes, as well as endothelial and many epithelial cells and secretions. Subtle differences in their structures cause major differences in antigenicity. Their common denominators are the types I and II core glycoconjugates, which are fucosylated in the bone marrow by H-(fucosyl) transferases into H-I and H-II respectively, before being added to the surface of erythrocytes. (11). The fucosylated glycans are the direct substrates for further glycosylation reactions that give rise to the epitopes for the A, B and Lewis blood group antigens. The ABO (or ABH) and Lewis BgAgs have been epidermiologically associated with susceptibility to several infectious agents.

Human blood group antigens (BgAgs) include H-I antigen, H-II antigen Lewis antigen Le^(b) and Le^(x) and Le^(y).

Human histo-blood group antigens, binding to the adherins, for example MOMP or FlaA, on Campylobacter prevent or reduce the ability of the Campylobacter to adhere to the epithelial cells of the gastrointestinal tract.

A synthetic human histo blood group antigen may be a molecule with the same chemical structure as a natural human histo blood group antigen but it is made outside of the human body, for example it may be made synthetically from suitable reagents or may be made in other organisms, such as bacteria, fungi or eukaryotes and expressed transgenically. In another embodiment a synthetic human histo blood group antigen may be a molecule that binds to the same part of MOMP or FlaA as a natural human histo blood group antigen. A synthetic human histo blood group antigen may be a sugar or a glycoprotein or a glycolypid. The synthetic human histo blood group antigen may be purified using one or more purification steps, for example chromatography steps, before being used in the method of the present invention.

A synthetic human histo-blood group antigen may be used to inhibit the binding or adhesion between MOMP and/or flaA and epithelial cells. It may bind to MOMP and/or FlaA and prevent or reduces MOMP or FlaA adhesion to epithelial cells and reduce or prevent colonisation of the gastrointestinal tract of an animal with Campylobacter.

A synthetic human histo-blood group antigen may be a sugar, for example a saccharide having the same structure as a natural human histo-blood group antigen such as for example H-I antigen, H-II antigen, Lewis antigen, Le^(b) Le^(x) or Le^(y).

The compound used in the method of the present invention may be a compound that has a structure that is different from a natural human histo-blood group antigen but that adheres to MOMP and/or FlaA and prevents or reduces MOMP or FlaA adhesion to epithelial cells and reduces or prevents colonisation of the gastrointestinal tract with Campylobacter. The compound may be a sugar or an oligosaccharide.

Preferably the compound is a molecule that adheres to MOMP. Suitably the compound is a molecule that can interact with loop 7 of MOMP in the glycosylated or unglycosylated form.

The compound used in the method of the present invention may be ferric quinate. The compound used in the method of the present invention may have one of the following structures:

The compound used in the method of the present invention may have a structure similar to that of Ferric Quinnate. The compound used in the present invention may be a compound with a structure similar to the structure of a human histo blood group antigen.

The compound used in the method of the present invention may be administered orally. This is advantageous because it is easy to administer compounds orally to animals. Oral administration is also a preferred method of administering a compound to ensure that it reaches the gastrointestinal tract.

Preferably the compound may be administered in an animal's feed or drinking water.

In the method of the present invention the compound may be administered to the animal at any time during its lifetime. In one embodiment the compound is administered to the animal at least once a day for a period of time before slaughter of the animal. For example the compound may be administered to the animal for between 1 and 10 days, preferably for between 1 and 8 days, between 1 and 6 days, between 1 and 4 days, before slaughter or for 2 or 1 days. In one embodiment a single dose of the compound may be administered to the animal between 1 and 4 days before slaughter. In one embodiment the compound may be administered to the animal every day for 3 days, 4 days or 5 days before slaughter. Chickens are often colonized by Campylobacter between 7 and 10 days before slaughter. Therefore in one embodiment the compound may be administered to a chicken less than 10 days before slaughter to disinfect the chicken and reduce colonisation of the gastrointestinal tract of the chicken before slaughter. In another embodiment the compound of the present invention may be administered to an animal before colonisation of the gastrointestinal tract of the animal with Campylobacter in order to prevent colonisation of the gastrointestinal tract of the animal with Campylobacter. In one embodiment the compound of the present invention is administered to a chicken more than 10 days before slaughter to prevent transmission of Campylobacter within a flock of chickens.

It is advantageous to administer the compound to the animal a short time before slaughter because the animal the amount of Campylobacter in the gastrointestinal tract of the animal is reduced at the time of slaughter so that there is a lower risk of contamination of the carcass with Campylobacter.

In one embodiment of the present invention the compound may be administered to an animal at a dosage of 0.3-32 mg/day/kilo as a solution having a range of concentration from 34-340 μM (0.02-0.2 g/L). A concentration of 0.2 g/L has an effect on colonization during the first three days post-infection and also on the binding of Campylobacter to blood group antigens may be reduced by 60%. In another embodiment the compound may be administered at a concentration of 2 g/L, which may prevent Campylobacter colonisation of the gastrointestinal tract of the animal and/or reduce the number of Campylobacter in the gastrointestinal tract of the animal to substantially zero.

In another embodiment the present invention provides a method for reducing the amount of Campylobacter in meat comprising the steps of:

Providing an animal with a compound as defined in any one of the preceding claims; and preparing a meat product from the animal. The animal may be any type of animal, preferably a poultry bird, preferably a chicken.

In another embodiment the present invention provides a method for identifying a compound for use in disinfection of animals, preventing or reducing adhesion of Campylobacter to the gastrointestinal tract or treatment of Campylobacter infection in humans or animals, said method comprising the steps of:

-   -   a) providing a simulation of MOMP or glycosylated MOMP;     -   b) selecting a candidate molecule that fits within the cavity         between loops 4 and 7 of MOMP or selecting a candidate molecule         which interacts with at least one of amino acid residues Arg³⁵²,         Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ Ile³³⁷, Arg³⁸¹,         Asp²⁶¹ and Ser³⁹⁷ of MOMP.

Compounds may be selected by docking them into an in silico model of MOMP to find a molecule that fits into the binding site of MOMP where the human histo blood group antigen binds with MOMP.

Preferably the compound is a molecule that can interact with at least one of amino acid residues Arg³⁵², Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ Ile³³⁷, Arg³⁸¹, Asp²⁶¹ and Ser³⁹⁷ of MOMP.

Preferably the compound is a molecule that can interact with at least one or more of amino acid residues Arg³⁵², Lys²⁷⁸ and Lys³⁸⁵ of MOMP or at least one or more of residues Asn²⁵⁸ and Lys²⁷⁸ or at least the residues 352 and 385 of MOMP. The compound may interact with at least residues Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ and/or Ile³³⁷ of MOMP or at least one or more of residues Lys²⁷⁸, Arg³⁵² and Arg³⁸¹ of MOMP or at least one of Asp²⁶¹ and Ser³⁹⁷ of MOMP.

The major contributors in the interaction of glycosylated MOMP with Le^(b) are residues Arg^(352,381) and Lys²⁷⁸, whereas only residues 352 and 278 are involved in the interaction of non-glycosylated MOMP with Le^(b). Residues Arg^(352,381) are conserved in all sequences examined whilst residue Lys²⁷⁸ is semi-conserved and is replaced by Arg in some strains. The molecular properties of this amino acid suggests it would be able to mediate BgAg binding through hydrogen bond formation in a similar fashion to residues Arg^(352,381).

The present inventors have constructed an in silico model of glycosylated MOMP. The in silico model of MOMP may be used to identify amino acid residues that are in contact with various human histo-blood group antigens when they bind to MOMP. This in silico model allows the conformational changes that take place in MOMP when it is glycosylated to be studied. This can be advantageous because it allows selection of further compounds that could interact with MOMP, in particular compounds that can bind to the amino acids that have been identified. These compounds can then be tested in vivo or in vitro to check whether they bind to MOMP protein.

The adhesion of Campylobacter, in particular Campylobacter jejuni (C. jejuni) to human histo-blood group antigens is via the major subunit protein of the flagella (flaA) and the major outer membrane protein (MOMP). MOMP was shown to be glycosylated at Threonine²⁶⁸. This glycosylation was shown by in silico modelling techniques to have a notable effect on the conformation of MOMP and to increase adhesion of MOMP to human histo-blood group antigens.

Residues of MOMP that have been identified as binding to various natural human histo-blood group antigens include Arg³⁵², Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ Ile³³⁷, Arg³⁸¹, Asp261 and Ser³⁹⁷ of MOMP. It is advantageous to select candidate molecules that may be used in the present invention because they bind to MOMP by interacting with one or more of these residues in the structure of MOMP.

Once compounds have been selected in silico, they may made and tested to measure the binding to MOMP protein in vitro or in vivo. A quantity of the selected compound can be prepared for use in the methods of the present invention.

Compounds that are useful in the method of the present invention may be included in animal feed, as a feed ingredient or as a feed supplement. The animal feed, feed ingredient or feed supplement may be suitable for any animal, in particular animals that are to be slaughtered for human consumption, preferably poultry, more preferably chickens.

Compounds that are useful in the methods of the present invention may be provided to an animal in liquid or solid form or as a powder. They may be included as an ingredient in feed or animal food or as an ingredient in a feed or food supplement. In one embodiment the compounds are provided to chickens in chicken feed or as a feed ingredient mixed with chicken feed.

A feed may be a food intended for or suitable for consumption by animals. A food or a foodstuff may be a food that is intended or suitable for consumption by humans.

The present invention provides a method of disinfecting a foodstuff or a food comprising administering a compound as defined in any one of the preceding claims in an effective amount to the foodstuff to reduce the amount of Camylobacter in the foodstuff.

This is advantageous because it reduces the risk of infection with Campylobacter of humans who consume the foodstuff.

A foodstuff or a food may be for human consumption, in particular the food may be a meat product, for example a fresh meat product, a processed meat product, a chilled meat product, a frozen meat product or a cooked meat product. The meat product may be, for example a beef, lamb, pork, duck, chicken, goose, turkey, rabbit, fish or shellfish meat product. Preferably the meat product may be a poultry meat product, more preferably a chicken meat product.

The present invention also provides a compound as defined in the present invention for use in the prophylaxis or treatment of Campylobacter infection in humans. A compound as defined in the present invention may be used in the manufacture of a medicament for the prophylaxis or treatment of Campylobacter infection in humans.

The compound may be provided to humans to prevent or treat infection of humans with Campylobacter (campylobacteriosos). This is advantageous because the compounds prevent or reduce adhesion of Campylobacter to the epithelial cells in the gastrointestinal tract. This may prevent or reduce infection with Campylobacter because Campylobacter adheres to cells in the human gastrointestinal tract by docking onto human histo-blood group antigens that are expressed on the cells of the gastrointestinal tract. The compounds may compete with natural human histo-blood group antigens that are on the epithelial cells for binding of MOMP and FlaA and therefore reduce the amount of binding of Campylobacter to the cells.

The in silico model of MOMP may be used to develop or refine a vaccine against Campylobacter for use in humans.

The in silico model of MOMP may be used to develop or refine a vaccine against Campylobacter for use in birds, preferably poultry, more preferably chickens.

Subunit (or killed) vaccines have a number of advantages over live vaccines, including safety and ease of production, storage and distribution. To date only limited success has been achieved with subunit vaccines administered orally. The reason for this is assumed to be the lack of oral delivery to the appropriate site for development of immune-mediated protection. The assumption is that the most appropriate site would be the intestinal mucosa. Such delivery requires the presentation of antigen with a mucosal adjuvant. Currently there are no known mucosal adjuvants for birds.

Recently a number of delivery systems have been developed for mammalian mucosal vaccination regimes. One such system utilises a non-ionic, hydrophilic immunomodulator, Pluronic block copolymer F127, and the polysaccharide chitosan formulated into microspheres (Lee, Da Silva et al. 2008). Chitosan is used in a number of biomedical applications because of its bioavailability, biocompatibility, biodegradability, high charge density and non-toxicity. In addition this material has been shown to weaken the tight junctions of epithelial cell layers allowing the uptake of antigen and to reduce the rate of mucociliary clearance reducing antigen removal. Although this material appeared to be valuable in the development of mammalian vaccines and drug delivery systems it had not been tested in birds.

The microspheres were made using an ionic gelation process with tripolyphosphate (TPP). Briefly, 0.25% chitosan in 2% acetic acid was added drop-wise to 15 w/v % TPP under magnetic stirring. The mixture was sonicated and the MS beads removed from the TPP solution by centrifugation, washed with distilled water and resuspended in PBS. The antigens were then loaded onto the beads by co-incubating overnight at 37° C. After incubation, the suspension was centrifuged to separate the beads from unloaded antigens (MOMP/FlaA). The levels of antigen uptake were determined by protein concentration assays of protein solutions pre- and post-loading.

The present invention provides a method of treating or preventing Campylobacter infection in humans comprising administering to the human an effective amount of a compound as defined in any one of the preceding claims.

The present invention provides a kit comprising:

-   -   a) at least one compound as described in the present invention         and optionally instructions for using the kit.

There now follows by way of example only a detailed description of the present invention with reference to the accompanying drawings, in which;

FIG. 1 shows the competitive effect of the soluble glycoconjugates, i.e. H-II, Lc^(b) or Le^(y) on attachment of strain NCTC11168 to a series of BgAs. A) An ELISA plate was coated with a selection of BgAgs. Specific binding was calculated by subtracting the BSA (negative control) values from the BgAg absorbance. Binding of strain NCTC11168 to BgAgs was inhibited significantly (p<0.05) by pre-incubation of cells with soluble glycoconjugates prior to adding them to the ELISA plate. Error bars; mean of triplicate values±SEM, number of repeating experiments was 3. Each group of bars, from left to right, NCTC11168, NCTC11168-H-II, NCTC11168-Leb, NCTC11168-Ley.

B) Identification of BgAg-binding proteins from strain NCTC11168 by using Re-Tagging method. Two proteins were identified at sizes of 45 and 59 kDa, corresponding to MOMP and FlaA, respectively.

FIG. 2 shows A) Inhibition of binding of strain NCTC11168 to H-II glycoconjugate in the absence of an inhibitor (non-treated, NT) and in the presence of purified MOMP of Cj-281 (MOMP(−)), low binder strain, S3—Table 1). Purified MOMP from NCTC11168 (MOMP(+)), and pre-incubation of NCTC11168 bacterial cells with H-II glycoconjugate (H-II). Pre-treatment of all examined MOMP and H-II had significantly reduced (p<0.001, ***) the bacterial binding to H-II antigen. In contrast, MOMP(−) had a lower effect compared with H-II or MOMP(+) due to the lower affinity for the H-II antigen. B) ELISA plate was coated with a selection of BgAgs. Specific binding was calculated by subtracting the BSA (negative control) values from the BgAg absorbance at 405 nm. Strain NCTC11168 and Cj-266 (high binder strain, S3—Table 1), and corresponding ΔflaA mutants, have been examined for binding to Le^(b), H-II, H-I, Le^(x) and Le^(a). t-test confirmed the reduction in binding seen with mutants are significant (Le^(b); p=2.5E-05, H-II; p=0.012, H-I; p=0.001, Le^(x); p=0.029 and Le^(a); p=0.000) in strain NCTC11168. However, Cj-266ΔflaA mutation had no effect on binding, which indicates the binding capacity was compensated by MOMP protein. Each group of bars from left to right: NCTC11168, 11168-ΔflaA, Cj-266, Cj-266ΔflaA. C) A double mutant (DM) of ΔflaA and single substitution of glycosylation site in MOMP protein (Thr²⁶⁸ was substituted with Gly) was constructed in both strain NCTC11168 and Cj-266, and the binding to Le^(b) H-I and H-II was examined. The binding was significantly reduced in NCTC11168-MOMP^(T/G) but the reduced binding was not significant in Cj-266-MOMP^(T/G). Although, t-test confirmed the reduction in binding seen with NCTC11168-DM and Cj-266-DM the mutants are significant (p<0.05). Each group of bars from left to right: Leb, H-II, H-I.

FIG. 3 shows an overview of the mass spectrometry analysis by LC-MS/MS for both protein identification and glycosylated peptide characterization. A) Base peak chromatogram: Tryptic peptides are loaded on an on-line coupled C18 column and eluted into the mass spectrometer for analysis. B and C) MS precursor scan of the doubly charged glycosylated peptide at m/z 978.91 C) CID-MS/MS spectrum of the selected ion. D) Detection of glycan constituent of purified MOMP from different strains using biotinylated labeled lectins. GSL II: Griffonia (Bandeiraea) simplicifolia lectin II, DSL: Datura Stramonium lectin, ECL: Erythrina cristagalli lectin, LEL: Lycopersicon esculentum (tomato) lectin, STL: Solanum tuberosum (potato) lectin, VVA: Vicia villosa agglutinin and Jacalin: Artocarpus integrifolia lectin.

Jacalin lectin showed significant binding to NCTC11168 purified MOMP than the other used lectins. Jacalin lectin specifically recognizes Galβ1-3GalNAcα₁-Ser/Thr (T-antigen) and/or GalNAc. E) Further analysis was revealed by using an antibody against the T-antigen to confirm Jacalin specificity. MOMP(s) purified form strains 255, 281 (low binder clinical isolates) and MOMP^(T/G) didn't reveal significant binding to either Jacalin lectin or anti-T antigen compared with MOMP purified from strain NCTC11168 wild type. Error bars=mean of triplicate values±SED, No 2. Two independent experiments (P value). For each pair of bars: left hand bar—Jacalin lectin, right hand bar—Anti-Tantigen.

FIG. 4 shows a representation of MOMP (A, right) and glycosylated MOMP (A, left) in the approximate boundaries of the hydrophobic part of the outer membrane (OM). B), the superimposed lowest energy structure of MOMP (green) on the lowest energy structure of glycosylated MOMP (magenta) with RMSD of 1.291. Loops are shown in colours; β strands are green, L1 (residues 41-60, red), L2 (residues 87-109, magenta), L3 (residues 128-147, orange), L4 (residues 169-200 yellow) L5 (residues 227-233, black), L6 (residues 256-274, blue), L7 (residues 296-333, gray), L8 (residues 360-379, cyan) and L9 (residues 399-414, purple).

FIG. 5 shows a stereo cartoon of the MOMP backbone viewed from the extracellular side: β strands are green, L1 (red), L2 (magenta), L3 (orange), L4 (yellow) L5 (black) (L5), L6 (blue), L7 (gray), L8 (cyan) and L9 (purple) and its side view. The conformational changes in the glycosylate group induced by introduction of the ligands into the cavity of glycosylated MOMP. The complexes with Le^(b) (A) and H-II (D). In addition, hydrogen bonds shown in light blue involved in the interactions of MOMP (B and E) and its glycolysated form (C and F) with Le^(b) and H-II respectively in their active sites.

FIG. 6 shows examples of compounds that can be used in the present invention.

FIG. 7 shows the effect of a series of histo blood group antigens on biofilm formation. Comparison of biofilm formation between NCTC11168-WT, and corresponding mutants, Δfla A and MOMP-T/G in presence and absence of free sugars. A) The most significant decrease in biofilm formation is seen in wild type strain compared to the mutants. However, the biofilm formation of MOMP268T/G strain is comparable to ΔflaA, which indicate that O-glycosylation of MOMP also play important role for this formation. For each group of bars from left to right: NCTC11168, NCTC11168 (sugar), MOMP-T/G, MOMP-T/G(sugar). B) Similar results were observed except for core-II, other examined sugars significantly reduced the biofilm formation. For each group of bars from left to right: NCTC11168, NCTC11168(sugar), Δfla A, Δfla A (sugar).

FIG. 8 shows the lowest energy structure of MOMP from MD simulation with stereo cartoon of the MOMP backbone viewed from the extracellular side. MOMP forms hydrophilic channels through the outer membrane. The folding of β-barrel OMPs promotes trimer assembly and integration of the channel into the outer membrane. Moreover, two-dimensional crystallographic analysis showed that MOMP is structurally related to the family of trimeric bacterial porins.

CD spectroscopy analysis also demonstrated that the folded monomer mainly comprised β-sheet secondary structure, in agreement with the so called β-barrel structure of porins. MOMP folded monomers are able to form channels in artificial lipid bilayers with the same conductance properties as monomers embedded into trimers, which suggests that the folded monomer is the functional unit of the MOMP porin.

FIG. 9 shows molecules used in the modelling of molecules that bind to MOMP.

FIG. 10 shows colonisation levels of chicks challenged with wild-type campylobacter strain NCT11168-O or mutant campylobacter strain MOMP^(268T/G).

FIG. 11 shows Ferric-Quinate 1, 3, 4, 5-Tetrahydroxy Cyclohexan carboxylic acid

FIG. 12 shows the inhibitory potential of Ferric Quinate Fe(QA)3 on adherence of C. jejuni was analyzed by ELISA using BgAgs (Core-I, Core-II, H-I, H-II, Leb, Ley and Lex).

FIG. 13 shows the inhibitory potential of Ferric Quinate Fe(QA)3 on adherence of C. jejuni was analyzed by ELISA using BgAgs (Core-I, Core-II, H-I, H-II, Leb, Ley and Lex).

FIG. 14 shows colonisatin of chicks by C. jejuni 11168-O following FeQ (0.034 mM) treatment.

FIG. 15 shows colonisatin of chicks by C. jejuni 11168-O following FeQ (0.34 mM) treatment.

FIG. 16 shows metagenomic analysis of population treated with FeQ Genus/species level.

FIG. 17 shows metagenomic analysis of population treated with FeQ Phylum level. 1—Ley R, Backhed F, Turnbaugh P, Lozupone C, Knight R, Gordon J (2005). “Obesity alters gut microbial ecology”. Proc Natl Acad Sci USA 102 (31): 11070-5. doi:10.1073/pnas.0504978102. PMC 1176910. PMID 16033867 2—Ley R, Turnbaugh P, Klein S, Gordon J (2006). “Microbial ecology: human gut microbes associated with obesity”. Nature 444 (7122): 1022-3. doi:10.1038/4441022a. PMID 17183309. 3—Turnbaugh P, Ley R, Mahowald M, Magrini V, Mardis E, Gordon J (2006). “An obesity-associated gut microbiome with increased capacity for energy harvest”. Nature 444 (7122): 1027-31. doi:10.1038/nature05414. PMID 17183312.

Campylobacter jejuni is an important cause of human food-borne gastroenteritis. Despite the high prevalence and medical importance of C. jejuni infection, fundamental aspects of pathogenesis remain poorly understood, in particular the detailed molecular interactions between host and pathogen. Human histo-blood group antigens (BgAgs) are often targeted by mucosal organisms as levers for adherence prior to invasion. Using a retagging approach, the corresponding surface-exposed BgAgs-binding adhesins of C. jejuni were identified as the major subunit protein of the flagella (FlaA) and the major outer membrane protein (MOMP). O-glycosylation of FlaA has previously been reported, and is required for filament assembly and for modulating flagella functionality. Purified MOMP like FlaA was O-glycosylated. The O-glycosylation was localised to Thr²⁶⁸ and suggested as Gal_(β1-3)-(GalNAc)₃-α1-Thr²⁶⁸. Site-directed substitution of MOMP Thr²⁶⁸/Gly led to a significant reduction in binding to BgAgs. Furthermore, molecular dynamics (MD) simulation modelling techniques suggested that O-glycosylation of MOMP has a notable effect on the conformation of the protein.

Thus, C. jejuni uses O-glycosylation of surface-exposed proteins to modulate the conformation and binding capability.

Prevention and treatment of human infection with Campylobacter and its consequences are hampered by a poor understanding of the detailed molecular interaction between the host and the pathogen.

Studies by the present inventors have shown that C. jejuni specifically bind all human BgAgs, and identified the bacterial ligands responsible for binding. These are the flagellin protein FlaA and the major outer membrane protein MOMP.

The present studies have also found that MOMP is O-glycosylated, and shares a common BgAg binding site with FlaA, which has already been shown to be O-glycosylated. Glycosylation of MOMP causes it to undergo conformational changes which alters its affinity for binding of, and hence recognition of, BgAgs compared with unglycosylated MOMP protein. Conformational MOMP epitopes are important in host immunity, and variation in surface-exposed regions probably occurs as a result of positive immune selection during infection. Identification of the protein glycosylation profile of C. jejuni, in the outer membrane is helpful in understanding the diverse pathogenicity of C. jejuni strains among different hosts.

The present studies have created an in silico model of glycosylated MOMP, which have been used to identify the amino acids which mediate the bacterial binding to BgAgs. The model and the amino acids that are essential for binding to BgAgs may be used to identify candidate drug targets. The model may also be used to predict which molecules will bind to MOMP and can reduce the adhesion of the Campylobacter carrying MOMP to cell walls.

The present studies have found that BgAgs can inhibit bacterial adhesion and biofilm formation and have identified molecules that can be used (a) for treatment of humans suffering from Campylobacteriosis; (b) to prevent colonisation of chickens with Campylobacter ssp; and (c) to eliminate chicken colonisation in infected flocks.

Previous attempts to reduce the risk of human infection with Campylobacter ssp involved the use of vaccines employing nucleic acids encoding Campylobacter proteins, in particular flagellin (US2007/2049553).

This is completely different from the approach of the present invention which uses specific compounds to block the ligand binding site of the Campylobacter and hence inhibit Campylobacter adherence and colonisation in the chicken gastrointestinal tract. Compounds that are mimetics or synthetic human histo-blood group antigens and synthetic sugars such as Ferric Quinate (Fe-Q) may be used in the present invention.

EXAMPLES

C. jejuni Binds a Wide Range of Human BgAgs.

To determine the range and specificity of BgAgs that bind C. jejuni, Core-I, Core-II, H-I, H-II, Le^(b), Le^(x), and Le^(y) were immobilised in specialised 96-well ELISA plates and incubated with log-phase digoxigenin (Dig)-labelled C. jejuni strain NCTC11168. The strain bound to all the examined BgAgs, the degree varying only marginally between BgAgs (S1—Fig.).

Blood group antigens were obtained from IsoSep (Sweden). The lab strain (ATCC11168) was obtained from ATCC bank and the clinical strains from a collection belong to Prof. Julian M. Ketley (Department of Genetics, University of Leicester, Leicester LE1 7RH, UK).

Pre-incubation of bacteria or coated plates with soluble BgAgs inhibited the binding, confirming specificity (FIG. 1A). In addition, adhesion assays by co-culturing C. jejuni strain NCTC11168 and Caco-II cells was carried out. Soluble H-II caused significant reduction in bacterial binding to the host cells (S2—Fig.). In addition, the same range of immobilized BgAgs was used to test the ability of 39 clinical isolates of C. jejuni. All C. jejuni isolates bound to all examined BgAgs, albeit to a variable degree (S3—Table). Correlation analysis between each sugar and principal component analysis was performed. It enables a visualization of the correlations—the structurally closer (S4—Table) the sugars are to each other, the more similar they are in terms of binding capacity (S4—Fig.).

The high degree of specificity by H. pylori BgAg-binding adhesions is in contrast to our findings with C. jejuni, which appears to bind to a wide range of related antigens. This may reflect the fact that H. pylori has a very restricted host range (infecting only humans), whereas C. jejuni is able to establish infection in a wide range of birds and mammals and may have gained an evolutionary advantage by broadening its specificity and maximising its survival in different hosts.

C. jejuni FlaA and MOMP Mediate the Binding to a Wide Range of Human BgAgs.

For identification and purification of BgAgs-binding bacterial adhesins, a retagging technique was used. Two generated protein bands in FIG. 1B identified by mass spectrometry as the major outer-membrane protein (MOMP, 45 kDa) and FlaA (the major flagella component, 59 kDa), respectively. The C. jejuni MOMP is a multi-functional porin and is essential for bacterial survival; it is predicted to comprise outer membrane-spanning beta stands separating periplasmic and surface-exposed loops. That it is encoded by the porA gene which is extremely genetically diverse and the variability of the porA surface loops provides evidence that immune selection strongly influences the diversity of this protein. Interestingly, the greatest variation in both putative amino acid sequence and length was formed in loop 4.

MOMP was purified under native conditions from strain NCTC11168 and inhibition ELISA and confocal experiments showed that both purified MOMP and H-II significantly inhibited binding of NCTC11168 to H-II antigen (FIG. 2A). Deletion mutant of ΔflaA in strains NCTC11168 and Cj-266 (a clinical isolate, S3-Table) were constructed. This had significantly reduced the binding capacity to all examined BgAgs except for Le^(x) in strain NCTC11168 (FIG. 2B). By contrast, ΔflaA deletion in strain Cj-266 didn't exhibit reduced binding to BgAgs (FIG. 2B), which indicated that MOMP per se is sufficient for adherence to BgAgs.

Invasive properties could be partially restored by centrifugation of the mutants onto the tissue culture cells, indicating that motility is a major, but not the only, factor involved. Here, we identified the corresponding C. jejuni adhesins, which mediate the bacterial binding to BgAgs.

Ability of MOMP268T/G to Colonise Chicks

The ability of MOMP268T/G to colonise chicks was determined. 6-weeks old birds (n=10 per group) were challenged with 3×103 cfu wild-type strain NCTC11168-O or its isogenic mutant MOMP268T/G by oral gavage. Caecal colonisation levels were determined in birds from each group at 7 days post-challenge. The results show a significant reduction in the geometric mean colonisation levels in the caeca in the MOMP^(268T/G) group compared to the wild-type (See FIG. 10). In addition, the ability of the mutant strain to invade the chicken's liver was examined. The results showed that MOMP^(268T/G) was completely unable to invade compared to the wild-type strain. These results confirm the importance and biological relevance of MOMP glycosylation in the establishment of colonisation in vivo. Values less than 100 in FIG. 10 are arbitrary figures, and no campylobacter was recovered.

Ferric Quinate; an Inhibitor for C. jejuni Adherence

A number of phenolic compounds, including caffeic and quinic acids (Baqar et al.), have been shown to have high levels of antioxidant activity and other potentially health-promoting effects in vitro. Also, quinic acid occurs in tea, coffee, fruits and vegetables. In particular, plants use the low molecular mass D-(−)-quinic acid (Baqar et al.) for mobilization of Iron and further use of this metal by cellular structures in metabolic pathways (Menelaou et al., 2009).

Ferric quinate Fe(QA)3 was identified as having promising inhibitory effects in vitro and in vivo on C. jejuni adhesion to BgAgs.

The inhibitory potential of Ferric Quinate Fe(QA)3 on adherence of C. jejuni was analyzed by ELISA using BgAgs (Core-I, Core-II, H-I, H-II, Leb, Ley and Lex). C. jejuni was pre-incubated with 34 μM Fe(QA)3 and specific inhibition was also analyzed by post-treatment of C. jejuni with Fe(QA)3 which bound to BgAgs at the time. The result showed that Fe(QA)3 conferred a 90% inhibition of binding, while Quinic Acid alone provided no inhibition of C. jejuni binding to all examined BgAgs. In addition the results from the bacterial culture (MH) containing Fe(QA)3 approach also demonstrated reproducible inhibition of microbial adherence. In addition, the sequential passages (P) of bacteria to the new plate containing Fe(QA)3 didn't cause any resistance concerning the binding abilities (see FIGS. 12 and 13).

To further clarify the growth-effect properties of Fe(QA)3, we investigated the effect of adding Fe(QA)3 to the culture medium. Supplementation with the different concentrations of Fe(QA)3, (34 and 340 μM) did not affect the growth of C. jejuni NCTC11168 strain.

These inhibitory properties against C. jejuni adherence to BgAgs were analyzed in vivo. Ferric Quinate was used as an additive to water (0.034-0.34 mM) and as an inhibitor of C. jejuni NCTC11168 strain adherence to, and thus colonization, in the chicken intestinal tract. 6-weeks old birds (n=10 per group) were challenged with 3×103-5 cfu wild-type strain NCTC11168-O by oral gavage. Caecal colonisation levels were determined in birds from each group at 3 and 7 days post-challenge.

The complex reduced significantly the adhesion of C. jejuni (2-3 Log at 0.34 mM concentration) to the intestinal mucosa and epithelial lining by inhibiting the binding between bacterial adhesins, such as MOMP (confirmed by model), may FlaA, and the corresponding binding sites in the host intestinal epithelium see FIGS. 14 and 15.

In A Metagenomic analysis of population treated with FeQ at a Genus/species level a difference can be seen between FeQ treated and non-treated birds at day 7, there is a shift in the population with increase of Bacteriodetes phylum, especially Bacteroides feacalis (1, 2, 3).

MOMP is O-glycosylated.

Campylobacter specifically modify their flagellar proteins with O-linked glycans that can constitute up to 10% of the protein mass. These modifications are necessary for flagellum assembly, and thus affect secretion of virulence-modulating proteins, bacterial colonization of the gastrointestinal tract, autoagglutination and biofilm formation.

MOMP was purified from strains NCTC11168 and Cj-281 under native conditions and analysed by Nanoflow LC-MS/MS FT/ICR following in-gel protein digestion as described in A. Shevchenko, M. Wilm, O. Vorm, M. Mann, Anal Chem 68, 850 (Mar. 1, 1996). The migration of trypsin-digested MOMP peptides from both strains was essentially identical except for one peptide corresponding to amino acids 268-278, corresponding to the predicted loop 6: the strain NCTC11168 peptide showed a greater mass; MS/MS analysis confirmed that glycosylation of Thr-268 with a Hex-(HexN-acetylamine)₃ (where Hex can be Glucose or Galactose) was responsible for the observed shift (FIGS. 3A, B and C). FASTA sequence alignment of clinical isolates indicated that Thr-268 on loop 6 of strain NCTC11168 appears to be conserved in 52% of isolates.

Site-directed substitution of Thr²⁶⁸ to Gly was carried out on MOMP of strain NCTC11168 and a clinical isolate Cj-266 (yielding MOMP^(268T/G), S5—Table). This substitution caused a clear shift in the protein's migration, strongly suggesting the loss of its glycosylation (S5). The ability of this mutant to bind to a range of BgAgs in an ELISA assay was examined and it was shown to have a reduction in binding to each of examined BgAgs (FIG. 2A). Also, a reduced biofilm formation was observed, which indicates that O-glycosylation of MOMP plays an important role in this context (S8—Fig. A and B).

The Role of PglB and PseD Transferases on MOMP Glycosylation.

Flagellin is the only O-glycosylated C. jejuni protein to have been reported and glycans constitute ca. 10% to this protein's weight. The predominant O-glycans attached to the Campylobacter flagellum are derivatives of pseudaminic acid or legionaminic acid, which are C9 sugars that are related to sialic acids. In addition, the related human gastric pathogen H. pylori also O-glycosylates its flagella with Pse, similarly to C. jejuni, and modification is required for bacterial motility and flagellar assembly.

Interestingly, specific loss of Pse5Am due to mutation of the Pse biosynthesis A gene (pseA) in C. jejuni subsp. jejuni 81-176 resulted in loss of auto-agglutination and reduced adherence to and invasion of intestinal epithelial cells in vitro, and reduced virulence in the ferret model.

Also, PseD as a putative PseAm transferase showed that mutation in pseD lacked PseAm on flagellin and failed to auto-agglutinate.

The general protein glycosylation (Pgl) pathway involves several key “Pgl” enzymes, of which PglB is critical for protein N-glycosylation i.e. transfer of the first glycan molecules to the target proteins at specific Asn residues.

In order to evaluate the contribution of PseD and PglB transferases on C. jejuni MOMP glycosylation and its role on bacterial binding activity, a pglB deletion mutant was created in strain Cj81-176 and pseD deletion in strain NCTC11168; pglB deletion had no detectable impact on MOMP gel migration, glycan staining (data not shown), or bacterial binding to any of the examined BgAgs (S7—Fig. A). However, strain NCTC11168 pseD deletion resulted a significant reduction in binding to all examined BgAs and biofilm formation (data not shown).

These findings indicate that C. jejuni strain NCTC11168 encodes a transferase that is involved in post-translational modification of protein, which plays an important role in bacterial adhesion and reveals unusual post-translational modifications; an O-linked Hex-(HexNAc)₃ at Thr²⁶⁸. These post-translational modifications might undergo phase variation and may also vary in structure from one generation of C. jejuni to the next, and have a function in immune escape.

Moreover, these findings provide new insights into MOMP structure and resolve long-standing issues regarding the adhesion molecules which mediate the bacterial binding to the BgAgs. The pathogenesis and study the effects on processes such as colonization, invasion, and the ability to stimulate the host inflammatory response remain to be elucidated.

Determination of MOMP Glycan Composition.

Lectin kit was used for determination of the MOMP glycosylation constituent. The kit consists of 7 different lectins with overlapping specificity. The purified NCTC11168-MOMP in lectin array revealed significant binding to Jacalin lectin and in a lesser extent to GSL and LEL (FIG. 3D). Among the galactose-specific lectins, the lectin from Artocarpus integrifolia, known in the literature as Jacalin, exhibits specificity toward human tumour specific Thomsen-Friedenreich disaccharide (T-antigen, Galβ₁₋₃GalNAcα₁-Ser/Thr).

Moreover, to confirm the Jacalin binding specificity, monoclonal anti-T-antigen was used against purified MOMP isolated from different strains (NCTC11168-MOMP, NCTC11168 MOMP^(268T/G) and two clinical isolates with low binding activity; Cj281 and Cj-255). FIG. 3E shows that anti-T antigen antibody and Jacalin lectin reacted specifically with purified NCTC11168-MOMP. The observation that NCTC11168-MOMP interacts with Jacalin and anti-T antigen but not MOMP isolated from low binder strains and NCTC11168 MOMP^(268T/G) (FIG. 3E) indicates that strain NCTC11168-MOMP is likely to be the 0-linked trimeric form of T-antigen (Galβ₁₋₃GalNAcβ₁₋₄GalNAcβ₁₋₄GalNAcα₁-Thr²⁶⁸).

Glycosylation of MOMP with T-antigen presented herein provides an important insight on the role of glycosylation for C. jejuni binding activity to Lewis antigens and in MOMP immunogenicity. Further determination of the other N- and O-glycosylated outer membrane proteins may shed light into the development of a glycoconjugate based vaccine in the future.

The role of Glycan in MOMP Binding to BgAgs

The advances in computer technology and new modelling techniques have facilitated simulations of peptide folding at the atomic level. Although gram-negative bacteria possess quite different homology in primary sequences of their porins, they are remarkably similar in their beta-barrel structure. Hence, we employed the beta-barrel structure from Comamonas acidovorans (1E54.pdb) as a template and constructed our model based on this assumption. In order to understand better the role of MOMP glycosylation in C. jejuni binding to the BgAgs, here we present the construction and molecular dynamic properties of MOMP and its glycosylated form.

The initial structure was constructed and showed to have 9 loops and 18 beta-strands. The lowest energy structure obtained from molecular dynamics (MD) simulations at 300 Kelvin (K) is represented in S9—Fig. A and B. This structure was glycosylated at residue 268 with a glycosyl group. The lowest energy structure of glycosylated MOMP (gly-MOMP) obtained from MD simulations was superimposed on the lowest energy structure of MOMP to see the conformational changes induced by the introduction of glycosylation as presented in FIG. 4B. It shows that the major changes occur in loops 4, 6 and 7 constructed roughly of 169-200, 256-274 and 296-333 residues where loop 6 bears the glycosyl group. However, it shows that a small change appears in the barrels. The approximate boundaries of two proteins in the hydrophobic part of the outer membrane are indicated by horizontal lines as represented in FIG. 4A. Interestingly, the galactosyl residue has a favourable interaction with Arg³²⁸ residue as indicated in FIG. 4 but upon complex with H-II the glycosylated residue undergoes considerable conformational changes where this interaction vanishes and the group tends to move towards loop 4 to interact with Thr^(186 and 187) (FIG. 4A). In contrast, this conformational change did not occur in the case of gly-MOMP with Le^(b).

The MOMP protein has a canal-like cavity as seen in S9—Fig. A and B, which is expected to be capable of accommodating very large molecules. A mimic of Lewis antigen, type-1 Lewis carbohydrate determinant (Le^(b)) and type-2 H-II antigen (S9—Scheme 2) were docked into the cavity of MOMP and gly-MOMP. These complexes were computed for MD simulations. The average energies derived from MD simulations of complexes are listed in S9—Table. The introduction of the ligands within the cavity of MOMP leads to a remarkable effect on conformational changes in the loops, especially in loops 4 and 7. These two loops are the longest among the rest and obviously undergo significant conformational changes compared with others. Interestingly, it was found that gly-MOMP has a relatively stable structure since it shows that only loop 7 slightly undergoes conformational changes upon this complex. This may mean that glycosylation enhances the stability of the protein and allow it to be immunologically inert through molecular mimicry of its host.

Corresponding MOMP amino acids, which mediate binding to Le^(b) and H-II antigens. The interactions involved in the complexes of both proteins with Le^(b) and H-II are represented in FIG. 5A-F. The channel of these barrel proteins largely contains arginine and lysine residues, which are likely responsible for the recognition of these sugars. It is apparent that gly-MOMP has favourable interactions with Le^(b) compared to MOMP. The residues Arg³⁵², Lys^(278 and 385) seems to be the major contributor in the interaction of the glycosylated protein with Le^(b) via hydrogen bonds whereas only the residues Asn²⁵⁸ and Lys²⁷⁸ are involved in the interaction of MOMP with Le^(b). The residues 352 and 385 are the members of the beta-barrel 7, which are the part of loop 7. This loop, as mentioned earlier, mostly undergoes conformation changes during the molecular dynamic simulation (FIG. 4B). The glycosyl group interacts with this loop, thus leading to favourable conformational change for the interaction, and consequently resulting in a well-orientation of these residues to interact with Le^(b). The glycosyl group is sandwiched between loops 4 and 7, probably influencing the dynamics of these loops, thus contributing to the binding ability of the protein. Calculations also show that the glycosylated protein has more favourable van der Waals (vdw) interactions compared with MOMP. It appears that the residues Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵ and Ile³³⁷ are well-located over the hydrophobic surface of Le^(b) in the complex of gly-MOMP compared with MOMP (FIGS. 5B and C). This is reflected in 67 kcal/mol vdw energy difference between two complexes. It seems that H-II is bound to proteins with a similar mode to Le^(b). The residues Lys²⁷⁸, Arg^(352 and 381) are involved in the complex of both proteins with H-II (FIGS. 5E and F). The only difference is in the residues Asp²⁶¹ and Ser³⁹⁷, the first is involved in the complex of MOMP and the second in gly-MOMP. The very large binding energy obtained for the complex of H-II by MMPBSA could not be explained but it still shows that gly-MOMP binds to H-II better than MOMP itself.

The other outcome gathered from MD calculations is the conformation and alignment of the ligands within the cavities of two proteins. They show that both ligands have different conformational orientations in the active sites of the proteins as indicated in S9—FIGS. 2A,B.

In conclusion, although MD simulations were carried out in short MD simulation time and in implicit salvation medium, it still shows that glycosylation of major outer membrane proteins provides better conformational changes and consequently affinity for binding and hence recognition of Lewis antigens compared with its parent protein. Conformational MOMP epitopes are important in host immunity, and variation in surface-exposed regions probably occurs as a result of positive immune selection during infection. porA diversity has been exploited in genotyping studies using highly discriminatory nucleotide sequences to identify potentially epidemiologically linked cases of clinical manifestations of C. jejuni infection. Interestingly, the host immune response has been suggested to play a role in defining the more antigenically homogeneous clonal complexes, and this could also reflect niche adaptation. For example, alignment of MOMP sequences isolated from human and chicken associated strains demonstrates that they differ predominantly at loop 4, therefore variation of loop 4 could influence the bacterial binding ability and consequently niche adaptation.

Moreover, identification of protein glycosylation profile of C. jejuni, mainly those related to outer membrane, are fundamental to understanding the diverse pathogenicity of C. jejuni strains among different hosts. The model can be mined for sub-networks of biological interest, such as essential amino acid that suggest candidate drug targets. Importantly, some low confidence interactions may be found to be biologically significant by experimental validation.

The model for C. jejuni interaction to Le^(b) and H-II antigens mediated by MOMP generated here substantially increases our knowledge about the protein and its glycosylation and the role in interactions detected thus far for the C. jejuni outer membrane.

Thus, the structural glycobiology will play a key role in unravelling other glycan structures that mediate the host-bacteria interaction through MOMP/FlaA proteins, contributing decisively for identification and validation of new glycan receptors for these bacterial lectins. This information will be of major importance for the improvement and design of new therapies to overcome the C. jejuni infection.

Biofilm Formation

Auto-agglutination (AAG) has been demonstrated to be critical for virulence for a variety of pathogens, and can play a role in adherence, microcolony formation, biofilm formation, and resistance to acid and phagocytosis. In two previous studies on AAG of C. jejuni (N. Misawa, M. J. Blaser, Infect Immun 68, 6168 (November 2000) and N. J. Golden, D. W. Acheson, Infect Immun 70, 1761 (April 2002)), there appeared to be an association with adherence or invasion of intestinal epithelial cells.

The impact of flaA mutation and/or MOMP-T/G substitution on biofilm was examined. Biofilms were generated over 48 h on polystyrene plates at 42° C. under microaerophilic conditions, and stained with crystal violet before they were assessed by opacity measurement, using an ELISA reader at A₅₉₅. In control samples without sugar added, biofilm formation of strain NCTC11168-ΔflaA deletion and MOMP^(T/G) were significantly lower than wild type strain (WT). Already known from previous studies, O-linked glycosylation of flagellin is necessary for proper assembly of flagella filaments, also flaA mutation leads to reduction in biofilm formation due to reduced motility. To determine the role of host BgAgs in inhibiting biofilm formation, various antigens were added into the media inoculated with different strains. A reduced biofilm formation was observed in presence of free sugar structures in media; most dramatic drop is seen in WT. For wild type strain, the H-II produced the highest reduction by 90% and followed by Le^(b) structure with 80% compared with other examined BgAgs. Probably, the greater reduction is due to the higher affinity, which effects the equilibrium equation, and requires longer time for detachment of free sugar from surface molecules and prevents the biofilm formation.

Although, the stronger binding affinity more interruption in biofilm formation. These data suggest that BgAgs compete with AAG and biofilm determinants on flagellin and MOMP, also confirmed the validity of the model and underlined the critical role of O-glycosylation in biofilm formation (FIG. 7—Figure A and B).

This experiment was repeated and same pattern was achieved. Taking in account that position of plate might affect growth; we added the samples and its control in identical position on different plates. In addition, we took an aliquot from each sample and grow on CCDA, it showed that growth were equal in all.

The Lowest Energy Structure of MOMP Protein.

Functional and structural studies of outer membrane proteins from Gram-negative bacteria are frequently carried out using refolded proteins. Although several structures of bacterial OMPs (outer membrane proteins) are now available, a large number of these proteins are still structurally and functionally poorly characterized. A model was generated for C. jejuni MOMP to study the effect of glycosylation on MOMP conformation and also the role of it in bacterial binding activity. The model may be used for predicting the functions of uncharacterized proteins and for mapping functional pathways in C. jejuni and other prokaryotes. The data can provide a framework for understanding dynamic biological processes, such as the C. jejuni primary attachment to histo-blood group antigens.

Alignment of porA from Different Bacterial Isolates

CLUSTAL W (1.81) multiple sequence alignment using BLOSUM weight matrix, of Campylobacter jejuni major outer membrane sequences downloaded from the Uniprot Database (http://www.uniprot.org/). Also, three non-binder (NB) and three high binder (HB) clinical isolates were added into this series (in house sequencing). Amino acid positions refer to positions in strain NCTC11168 (P80672).

The alignment showed the major contributors of the interaction of the glycosylated MOMP with Le^(b) via hydrogen bonds are residues 352 (Arg), 381 (Arg), and 278 (Lys), whereas only the residues 352 and 278 are involved in the interaction of non-glycosylated MOMP with Le^(b). Amino acid sequence alignments indicating MOMP active sites of C. jejuni isolates from different patients has been sufficiently stable for this purpose. Interestingly, residue 278 (Lys) is semi-conserved in 16 isolates and was substituted by Arg which is able to mediate the binging through hydrogen bond in similar fashion as residues 381(Arg) and 352(Arg).

In addition, alignment of these sequences also demonstrates that they differ predominantly at loop 4 but the binding pocket between loop 4 and 7 is relatively conserved. A definitive study on MOMP host association would require glycosylation analysis data for isolates from a wide variety of hosts. A complicating factor in exploring these relationships for all C. jejuni may be their ability to colonize multiple hosts and thereby undergo exposure to many different immune responses.

Moreover, the glycosylation site Thr²⁶⁸ in the MOMP proteins was conserved in 52% of bacterial isolates aligned in this study, which indicate the importance role of Thr in 268 position.

Computational Modelling

All molecular dynamic simulations were conducted by using AMBER (version 10.0) (40) suite of programmes on the Linux/Intel PC cluster of TR-GRID maintained by TUBITAK (Scientific and Technologic Research Council of Turkey). Simulations were initiated using the following amino acid sequence SEQ ID No. 1(MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSG VLRYRYDTGNFDKNFVNNSNLNNSKQDHKYRAQVNFSAAIADNFKAFVQ FDYNAADGGYGANGIKNDQKGLFVRQLYLTYTNEDVATSVIAGKQQLNLI WTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQGADLLEHSNIS TTSNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQLWLAYWDQVAFFY AVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHANGNLFALKGSIEVN GWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNGDTG RNIFGYVTGGYTFNETVRVGADFVYGGTKTEAANHLGGGKKLEAVARVD YKYSPKLNFSAFYSYVNLDQGVNTNES ADHSTVRLQALYKF). The model was constructed using the idea of the similarity of secondary structure of these class of proteins. The core structure of MOMP was initiated by using the skeleton of outer membrane protein of anion-selective porin from Comamonas acidovorans (1E54.pdb) and Pseudomonas aeruginosa (2QTK.pdb) as described in S. Biswas, M. M. Mohammad, L. Movileanu, B. van den Berg, Structure 16, 1027 (July 2008), as a template to build the beta-barrels. A combination of HyperChem (HyperChem™ Professional 7.51), chimera (UCSF), and the LEaP module as implemented in AMBER was used to build the core and add the loops and turns. The initial structure was heated from 0 Kelvin (K) to 325 K with a restrain of 10 kcal mol⁻¹ {acute over (Å)}⁻² on residues of beta-barrels to avoid the effect of conformational changes in loops on beta-barrels for a period of 200 ps in four steps, followed by simulations from 0 K to 325 K for another period of 200 ps without any restrains in four steps. The system was further simulated at 300 K for a period of 8 ns. All molecular dynamics (MD) simulations were carried out using pmemd (Particle Mesh Ewald Molecular Dynamics) model of programme as implemented in AMBER. The ff99SB force field was employed and solvation effects were incorporated using the Generalized Born model, as implemented in AMBER. A lower energy structure was chosen and this was glycosylated at the residue 268 (Thr) with Gal(β 1-3)-GalNAc(β 1-4)-GalNAc(β 1-4)-GalNAc-α-linked to the protein as illustrated in Scheme 1 using xleap as implemented in AMBER. Glycam04 force field was used for carbohydrate unit. The charge on the oxygen of the site chain of Thr was changed from −0.6761 to −0.4599 and the atom type of OS was assigned. The angle and dihedral parameters for dimethylether (CT-OS-CG) and dimethoxymethane (H2-CG-OS-CT) were used for the glycosylated angle and dihedral for the carbohydrate linkage.

The system was minimized with 500 steps of steepest descent minimization followed by 500 steps of conjugate gradient minimization and heated at 400 K for a period of 10 ps to avoid bad contacts with a restrain of 10 kcal mol⁻¹ {acute over (Å)}⁻² on the protein backbone and to have the carbohydrate groups in a good shape. The system was heated from 0 K to 325 K for a period of 200 ps without any restrains, followed by simulation at 300 K for a period of 3.5 ns.

Root-mean-square deviation (RMSD) analysis for the complex system was carried out on the trajectories by the ptraj module of AMBER (v10). 3D structures were displayed using by Chimera (UCSF), and RMSD graphics are shown by XMGRACE package programme.

Docking calculations were performed to accommodate the Lewis antigen (Le^(b)) and H-II antigen as seen Scheme 2 within the cavity of the protein. Docking of the Le^(b) was carried out using DOCK 6.0. Docking was performed with default settings to obtain a population of possible conformations and orientations for Le^(b) at the binding site. Spheres around the centre of the binding pocket were defined as binding pocket for the docking runs. Since Dock 6.0 program employs sphgen to produce spheres and hence for technical reasons, sphgen cannot handle more than 99999 spheres, the residues forming loops were stripped off and thus the calculations of spheres and grids were only performed with the beta-barrels forming the cavity. Then the coordinates of the Le^(b) obtained was recorded and AM1-Bcc (Austian model with Bond and charge correction), atomic partial charges and atom types of general amber force field (GAFF) were assigned for it using antechamber as implemented in AMBER. Xleap was used to accommodate the Le^(b) within the cavity of MOMP with combine command as well as to produce topology/parameter and coordinate files. The atom type of Le^(b) was changed to those described in Glycam04 force field. The system was minimized, followed by MD simulation at 300 K for about 6.0 ns. The same procedure was applied to the glycosylated protein.

MM/PBSA Calculations: This study applies a second-generation form of the Mining Minima algorithm, termed M2, to analyze the binding reactions of host-guest complexes in water. The MM-PB/SA module of AMBER (v9) was applied to compute the binding free energy (ΔG_(bind)) of each complex using the MM/PBSA method. For each complex, a total number of 200 snapshots were extracted from the last 1 ns of the complex trajectories.

During conformational searching and the evaluation of configuration integrals, Welec is computed with a simplified but fast generalized Born model. The electrostatic solvation energy of each energy-well is then corrected toward a more accurate but time-consuming finite-difference solution of the Poisson equation. The dielectric cavity radius of each atom is set to the mean of the solvent probe radius 1.4 Å for water and the atom's van der Waals radius, and the dielectric boundary between the molecule and the solvent is the solvent-accessible molecular surface. The solvation calculations use a water dielectric constant of 80. The MM/PBSA method can be conceptually summarized as:

ΔG _(bind) =G _(complex) −[G _(host) +G _(ligand)]  (1)

G=E _(gas) +G _(sol) −TS  (2)

E _(gas) =E _(bond) +E _(angle) +E _(torsion) +E _(vdw) +E _(ele)  (3)

G_(sol) =G _(PB) +G _(SA)  (4)

H=E _(gas) +G _(sol)  (5)

G _(sol) =G _(PB) +G _(SA)  (⁶)

H=E _(gas) +G _(sol)  (7)

S_(tot) =S _(vib) +S _(trans) +S _(rot)  (8)

ΔG=ΔH−TΔS  (9)

where G_(complex), G_(host), and G_(ligand) are the absolute free energies of the complex, host and the ligand species respectively as shown equation (1). Each of them is calculated by summing an internal energy in gas phase (E_(gas)), a solvation free energy (G_(sol)), and a vibrational entropy term equation (eq 2). E_(gas) is Standard force field energy, including strain energies from covalent bonds and torsion angles as well as noncovalent van der Waals and electrostatic energies (eq 3). The solvation free energy, G_(sol), is calculated with a PB/SA model, which dissects solvation free energy as the sum of an electrostatic component (GPB) and a nonpolar component (GSA) as shown in eq. 8, S_(tot) is the total entropy comprising of translational (S_(trans)), vibrational (S_(vib)) and rotational (S_(rot)) entropies as gas phase for each species as shown in eq. 6. In present study the entropy term was not included in calculations.

Building and Developing Amber Parameters for the Inhibitors

1) Charge Derivation for the Inhibitor

The model was divided into two fragments, one included quinate caped with NHMe ((1) in FIG. 9) and another included N,N-bis-(2-aminoethyl)ethane-1,2-diamine core ((2) in FIG. 9), which was further simplified into N,N-dimethylethane-1,2-diamine caped with acetyl ((3) in FIG. 9). The first stage was to optimize quinate amide and acate amide residues. This was done with a QM method at a reasonably high level of theory, which was done with MP2/6-31G* employing Gaussian 03 package programme. The original x-ray structure of quinic acid was used for quinate amide. The next stage was to calculate an ESP for each of the two optimized geometries that can ultimately be read by the RESP programme. HF/6-31G* as the level of theory was used to derive ESP for two structures. The RESP programme implemented in amber was used to derive the charges for each fragment. The capes, acetyl and NHMe were removed from each fragment and the model was built using xleap. ff99SB library was used to build library file for the model, which includes parameters such as atom type, bond, angles and dihedral. The topology and coordinate files were recorded for the model.

2) Conformational Search Using Molecular Dynamic Simulation

The structure was minimized at a total of 1000 steps; 500 of steepest descent (ncyc=500) followed by 500 of conjugate gradient (maxcyc-ncyc) in vacuum, followed by heating from 0 K to 700 K at seven steps each with 100 ps. The system was further run at 700 K for 1 ns. Few conformational minima were chosen and they were and they were cooled down to 300 K, each of which was further run at 300 K for 5 ns. From these runs a few conformations with minimum energy were chosen and they were minimized amber then with quantum mechanical calculation at B3LYP/6-31G* level of theory to locate the structure with the lowest energy.

Alignment of porA from Different C. jejuni Isolates.

CLUSTAL W (1.81) multiple sequence alignment using BLOSUM weight matrix, of Campylobacter jejuni major outer membrane sequences downloaded from the Uniprot Database (http://www.uniprot.org/).Also, three non-bind (NB) and three high binder (HB) clinical isolates were added into this series from in house sequencing. Amino acid positions referred to in this application relate to the amino acid positions in strain NCTC11168 (P80672) SEQ ID No 1.

        10         20         30         40 MKLVKLSLVA ALAAGAFSAA NATPLEEAIK DVDVSGVLRY          50         60         70         80 RYDTGNFDKN FVNNSNLNNS KQDHKYRAQV NFSAAIADNF         90        100        110        120 KAFVQFDYNA ADGGYGANGIKNDQKGLFVR QLYLTYTNED         130        140        150        160 VATSVIAGKQ QLNLIWTDNA IDGLVGTGVK VVNNSIDGLT         170        180        190        200  LAAFAVDSFM AAEQGADLLE HSNISTTSNQ APFKVDSVGN         210        220        230        240  LYGAAAVGSY DLAGGQFNPQ LWLAYWDQVA FFYAVDAAYS         250        260        270        280  TTIFDGINWT LEGAYLGNSL DSELDDKTHA NGNLFALKGS        290        300        310        320  IEVNGWDASL GGLYYGDKEK ASTVVIEDQG NLGSLLAGEE         330        340        350        360  IFYTTGSRLN GDTGRNIFGY VTGGYTFNET VRVGADFVYG         370        380        390        400  GTKTEAANHL GGGKKLEAVA RVDYKYSPKL NFSAFYSYVN         410        420  LDQGVNTNES ADHSTVRLQA LYKF 

Annotation with “*”, “:”, “.” refers to identical, conserved, semi-conserved amino acid substitutions respectively.

Hb1  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB2  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB0  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Hb2  MKLVKLSLVAALAASAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  NB1  MKLVKLSLVAALAASAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q9F791  MKLVKLSLVAALAASAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Hb3  MKLVKLSLVAALAASAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  D3FNB0  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB1  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB8  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAA5  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB6  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LA95  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  P80672  (SEQ ID No. 1)  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAC5  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAA2  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB7  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB9  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LA91  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  NB2  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LA98  MKLVKLILVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  A3ZHA2  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q9F792  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAC0  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q0GF63  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LAB3  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFVN-NSNLNN  59  Q2LA93  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGTFDKNWGTPNSNLND  60  Q2LAA0  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGTFDKNWGTPNSNLND  60  Q2LAC1  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGTFDKNWGTPNSNLND  60  Q2LAC4  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGTFDKNWGTPNSNLND  60  Q2LA94  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGTFDKNWGTPNSNLND  60  Q2LA92  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFLN-NSNLNN  59  Q2LAA4  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFIN-NSNLNN  59  Q2LA89  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYDTGNFDKNFIN-NSNLNN  59  NB3  MKLVKLSLVAALAAGAFSAANATPLEEAIKDVDVSGVLRYRYETSN-DWSNANFGSGIS-  58  Q2LAA9  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYETSN-DWSNANFGSGIS-  58  B5QHE5  MKLVKLSLVAALAASAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LA96  MKLVKLSLVAALAASAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LAB4  MKLVKLSLVAALAASAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LA97  MKLVKLSLVAALAASAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LAA7  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q9F788  MKLVKISLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LA87  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LA90  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNANFGSGIS-  58  Q2LAA3  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYESSN-PWSNGNYGSGIS-  58  QOGF62  MKLVKLSLVAALAAGAFSAANATPLEEAIKDIDVSGVLRYRYDTSN-DWNNAGFGSGIS-  58  *****: *******.****************:**********::..   .    .*.:.   Hb1 SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAB2  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAB0  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Hb2  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  NB1  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q9F791  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Hb3  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  D3FNB0  SKQNHKYRAQVNFSAAIADNFKAFIQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAB1  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAB8  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAA5  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAB6  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LA95  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  P80672  (SEQ ID No. 1) SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANGIKNDQKGLFVRQLYLT 115  Q2LAC5  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVNNVKNAEKGLFVRQLYLT 115  Q2LAA2  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q2LAB7  NKQDHKYRAQVNFSAAIADDFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q2LAB9  SKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNTEKGLFVRQLYLT 115  Q2LA91  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  NB2  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q2LA98  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  A3ZHA2  NKQDHKYRAQVNFGAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q9F792  NKQDHKYRAQVNFGAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q2LAC0  NKQDHKYRAQVNFGAAIADNFKAFIQFDYNAVDGGT----GVGNVKNAEKGLFVRQLYLT 115  Q0GF63  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNVTNAEKGLFVRQLYLT 115  Q2LAB3  NKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNATNAEKGLFVRQLYLT 115  Q2LA93  SKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNKTNAEKGLFVRQLYLT 116  Q2LAA0  SKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNKTNAEKGLFVRQLYLT 116  Q2LAC1  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAVDGGT----GVDNATNAQKGFFVRQLYLT 116  Q2LAC4  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAVDGGT----GVDNATNAQKGFFVRQLYLT 116  Q2LA94  SKQDHKYRAQVNFSAAIADNFKAFIQFDYNAVDGGT----GVDNATNAEKGLFVRQLYLT 116  Q2LA92  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAVDGGT----GVDNATNAEKGLFVRQLYLT 115  Q2LAA4  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGT----GVDNATNAQKGLFVRQLYLT 115  Q2LA89  SKQDHKYRAQVNFSAAIADNFKAFVQFDYNAADGGY----GANEIKNDQKGLFVRQLYLT 115  NB3  GKQDHKYRAQVNFGAASADNFKAFVQFDYSQADGGY----GADSISNTSDTLSVRQLYLT 114  Q2LAA9  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GADSISNTSDTLSVRQLYLT 114  B5QHE5  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GADSISNTSDTLSVRQLYLT 114  Q2LA96  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GADSISNTSDTLSVRQLYLT 114  Q2LAB4  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GTDSISNTSDTLTVRQLYLT 114  Q2LA97  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GTDSISNTSDTLTVRQLYLT 114  Q2LAA7  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GTDSISNTSDTLTVRQLYLT 114  Q9F788  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GTDSISNTSDTLTVRQLYLT 114  Q2LA87  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GTDSISNTSDTLTVRQLYLT 114  Q2LA90  GKQDHKYRAQVNFSGAISDNFKAFVQFDYNSQDGGY----GADSISNTSDTLTVRQLYLT 114  Q2LAA3  GKQDHKYRAQVNFNTAIADNFKAFVQFDYNSKDGGY----GENSISNTSDTLSVRQLYLT 114  QOGF62  GKQTHNYRAQINFSGAIADNFKAFVQFDYAAVDGGYNVTNGTGNQRNDQNSLTVRQLYLT 118  .** *:****:**. * :*:****:****   ***     * .   * .. : *******  Hb1 YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  Q2LAB2  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  Q2LAB0  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  Hb2  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  NB1  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q9F791  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Hb3  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVANNSIDGLTLAAFAVDSFMAEEQG 175  D3FNB0  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LAB1  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LAB8  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LAA5  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LAB6  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LA95  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAAEQG 175  P80672  (SEQ ID No. 1) YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  Q2LAC5  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LAA2  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LAB7  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LAB9  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LA91  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  NB2  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGIKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LA98  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGIKVVNNSIDGLTLAAFAADSFMAAEQG 175  A3ZHA2  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q9F792  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q2LAC0  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAADSFMAAEQG 175  Q0GF63  YTNEDVATSVIAGKQQLNFIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAAEQG 175  Q2LAB3  YTNEDVATSVIAGKQQLNLIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMTAEQG 175  Q2LA93  YTNEDVATSVIAGKQQLNIIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAAEQG 176  Q2LAA0  YTNEDVATSVIAGKQQLNIIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAVDSFMAAEQG 176  Q2LAC1  YTNEDVATSVIAGKQQLNIIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMATEQG 176  Q2LAC4  YTNEDVATSVIAGKQQLNIIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMATEQG 176  Q2LA94  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMATEQG 176  Q2LA92  YTNEDVATSVIAGKQQLNIIWTDNGVDGLVGTGVKVVNNSIDGLTLAAFAVDSFMATEQG 175  Q2LAA4  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAVDSFMAEEQG 175  Q2LA89  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVINNSIDGLTLAAFAVDSFMAAEQG 175  NB3  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEEVPA 174  Q2LAA9  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEEVPA 174  B5QHE5  YTNEDVATSVIAGKQQLNTIWTDNAIDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LA96  YTNEDVATSVIAGKQQLNTIWTDNAIDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LAB4  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LA97  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LAA7  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q9F788  YTNEDVATSVIAGKQQLNTIWTDNGIDGLVGTGVKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LA87  YTNEDVATSVIAGKQQLNTIWTDNAIDGLVGTGVKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LA90  YTNEDVATSVIAGKQQLNFIWTDNAIDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEASDT 174  Q2LAA3  YTNEDVATSVIAGKQQLNTIWTDNGVDGLVGTGIKVVNNSIDGLTLAAFAMDSFNEASDT 174  QOGF62  YTNEDVATSVIAGKQQLNTIWTDNDIDGLVGTGIKVVNNSIDGLTLAAFAVDSYNTDE-- 176  ****************** ***** :*******:** ************* **:  Hb1  AD----------LLGHS-TTS----TTQKAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB2  AD----------LLGHS-TTSTTH-TTQKAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 223  Q2LAB0  AD----------LLGHS-TTS----TTQKAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Hb2  AD----------LLGQS-TIS----TTQNAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  NB1  AD----------LLGQS-TIS----TTQNAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q9F791  AD----------LLGQS-TIS----TTQNAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Hb3  AD----------LLGQS-TIS----TTQNAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  D3FNB0  AD----------LLGKS-TIS----TTQKAAPFQADSLGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB1  AD----------LLGQS-TIS----TTQKAAPFQADSLGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB8  AD----------LLGQS-TIS----TTQKAAPFQADSLGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAA5  TD----------LLGQS-TIS----TTQNTAPFQADSLGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB6  TD----------LLGQS-TIS----TTQNTALFQADSLGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LA95  AD----------LLGHSNTST----ATPNQVPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 221  P80672  (SEQ ID No. 1) AD----------LLEHS-NIS----TTSNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAC5  AD----------LLGHS-NIS----TTSKQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAA2  AD----------LLGHS-TTSTT----QATAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB7  AD----------LLGHS-TTSTT----QATAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB9  AD----------LLEHS-TISTT----QNAAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LA91  AD----------LLGHS-NISTT---NANQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 221  NB2  AD----------LLGHS-NIST----TPNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LA98  AD----------LLGHR-NISTI---TPNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 221  A3ZHA2  AD----------LLGHS-NISTT---S-NQVPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q9F792  AD----------LLGHS-NISTT---S-NQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAC0  AD----------LLGHS-NTSTA---TPNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 221  Q0GF63  AE----------LLGHS-NIS----TTSNQAPFKVDSVGNLYGAAAVGSYDLAGGQFNPQ 220  Q2LAB3  AD----------LLGHN------------GSQFNPDSIGNLYGAAAVGSYDLAGGQFNPQ 213  Q2LA93  SD----------LVG------------ANN-TFKVDSIGNLYGAAAVGSYDLAGGQFNPQ 213  Q2LAA0  SD----------LVG------------ANNSTFKVDSIGNLYGAAAVGSYDLAGGQFNPQ 214  Q2LAC1  SD----------LVG------------HNGSQFNPDSIGNLYGAAAVGSYDLAGGQFNPQ 214  Q2LAC4  SD----------LVG------------HNGSQFNPDSIGNLYGAAAVGSYDLAGGQFNPQ 214  Q2LA94  SD----------LVG------------HNGSKFSPDSIGNLYGAAAVGSYDLAGGQFNPQ 214  Q2LA92  SD----------LLGQSTYVSND---KNNNDSFKLDSIGNLYGAAAVGSYDLAGGQFNPQ 222  Q2LAA4  AD----------LLGHS-NIS--S-AN-NSAPFKLDSIGNLYGGAAVGSYEFLGGQFNPQ 220  Q2LA89  AD----------LLGHS-NIS--S-AKPNIAPFKLDSIGNLYGGAAVGSYEFLGGQFNPQ 221  NB3  TT-----------TNG-FNKGNV--NGDGDVSSALDWSKNIYGAAAIGSYDLIGGQFNPQ 220  Q2LAA9  TT-----------TNGNFNKGNV--NGDGDVSSALDWSKNIYGAAAIGSYDIAGGQFNPQ 221  B5QHE5  TVTITQD-NSQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 231  Q2LA96  TVTITQD-NSQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGATAIGSYDIAGGQFNPQ 231  Q2LAB4  TVTITQD-SNQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 231  Q2LA97  TVTITQN-SSQKITGVQFNRGNP--KGDGDVSGALDWSKNIYGAAAIGSYDITGGQFNPQ 231  Q2LAA7  TVTITQD-NNQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 231  Q9F788  TVTITQD-NNQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 231  Q2LA87  TVTITQD-NNQKITGVQFNRGNP--KGDSDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 231  Q2LA90  TVTITQN-GSQKITGVQFNRGNP--KGDGDASGALDWSKNIYGAAAIGSYDLAGGQFNPQ 231  Q2LAA3  TVIITQDPSSNKITGVQFNRGNP--KGDGDVSGALDWSKNIYGAAAIGSYDIAGGQFNPQ 232  QOGF62  -------------QGYKDNNGRPDLTYTGDASQYLTWG-NIYGAAAVGSYDLAGGQFNPQ 222                                         *:**.:*:***:: *******                                    (Ser 262)  (Thr 268)  Hb1  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAB2  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 274  Q2LAB0  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Hb2  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  NB1  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q9F791  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Hb3  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  D3FNB0  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELNDKRHAN--------- 271  Q2LAB1  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKRHAN--------- 271  Q2LAB8  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAA5  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKRHAN--------- 271  Q2LAB6  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKRHAN--------- 271  Q2LA95  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDTTHAN--------- 272  P80672  (SEQ ID No. 1) LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAC5  LWLAYWDQVTFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAA2  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAB7  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LAB9  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LA91  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 272  NB2  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q2LA98  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 272  A3ZHA2  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDKTHAN--------- 271  Q9F792  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDQAHAN--------- 271  Q2LAC0  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDTTHAN--------- 272  QOGF63  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTIEGAYLGNSIDSELDDTTHTN--------- 271  Q2LAB3  LWLAYWDQVAFFYALDASYSTTIFDGINWTLEGAYLGNSVDSDLDSTRYAN--------- 264  Q2LA93  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSVDSDLNSAEHAN--------- 264  Q2LAA0  LWLAYWDQVAFFYALDVSYSTTIFDGINWTLEGAYLGNSLDSELNDKTYAN--------- 265  Q2LAC1  LWLAYWDQVAFFYALDASYSTTIFDGINWTLEGAYLGNSVDSDLDSAKYAN--------- 265  Q2LAC4  LWLAYWDQVAFFYALDASYSTTIFDGINWTLEGAYLGNSVDSDLDSARYAN--------- 265  Q2LA94  LWLAYWDQVAFFYALDASYSTTIFDGINWTLEGAYLGNSVDSDLNSAEYAN--------- 265  Q2LA92  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSLDSELDDRTYAN--------- 273  Q2LAA4  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSIDSELDKTTHTN--------- 271  Q2LA89  LWLAYWDQVAFFYAVDAAYSTTIFDGINWTLEGAYLGNSIDSELDDKTHTN--------- 272  NB3  LWLAYMSDNAFLYALDAAYSTTIFDGINWSIEGAYLGNSVDNKLKDRLDAA--------N 272  Q2LAA9  LWLAYMSDNAFLYALDAAYSTTIFDGINWSIEGAYLGNSVDNKLKDRLDAA--------N 273  B5QHE5  LWLAYMSDNAFLYALDATYSTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q2LA96  LWLAYMSDNAFLYALDATYSTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q2LAB4  LWLAYMSDNAFLYALDAAYSTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q2LA97  LWLAYMSDNAFLYALDAAYSTTIFDGINWSIEGAYLGNSVDNKLKDRLGVA--------N 283  Q2LAA7  LWLAYMSDNAFLYALDAAYSTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q9F788  LWLAYMSDNAFLYALDAAYSTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q2LA87  LWLAYMSDNAFLYALDAAYSTTIFNGINWTIEGAYLGNSVDNKLKDRLDAA--------N 283  Q2LA90  LWLAYMSDNAFLYALDAAYSTTIFDGINWTIEGAYLGNSVDNKLKDRLNVA--------N 283  Q2LAA3  LWLAYMSDNAFLYALDAAYNTTIFDGINWTIEGAYLGNSVDNKLKDRLDAA--------N 284  QOGF62  LWLAYMSDNAFLYALDLAYNTTIFDGINWSIEGAYLGNSVDNKLKDRFHAAGDPESSAAN 282  ***** .: :*:**:* :*.****:****::********:*..*..   .  (Lys 278) Hb1  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB2  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 334  Q2LAB0 GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Hb2  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  NB1  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q9F791  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Hb3  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  D3FNB0 GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB1  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB8  GNLFALXGTIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAA5  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB6  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LA95  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 332  P80672  (SEQ ID No. 1) GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAC5  GNLFALXGTIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAA2  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB7  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAB9  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LA91  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 332  NB2  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LA98  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 332  A3ZHA2  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q9F792  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 331  Q2LAC0  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 332 Q0GF63  GNFFALKGGIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLSSLLAGEEIFYTTGSRLNG 331  Q2LAB3  GNFFALKGGIEVNGWDASLGGLYYGDKEKASTVIIDDQGNLSSLLAGEEIFYTTGSRLNG 324  Q2LA93  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 324  Q2LAA0  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVAIEDQGNLGSLLAGEEIFYTTGSRLNG 325  Q2LAC1  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 325  Q2LAC4  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 325  Q2LA94  GNLFALKGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 325  Q2LA92  GNLFALXGSIEVNGWDASLGGLYYGDKEKASTVVIEDQGNLGSLLAGEEIFYTTGSRLNG 333  Q2LAA4  GNLFALRGSVELNGWDASLGGLYYGDKEKASTVVIEDQGNIGSLLAGEEIFYTTGSRLNG 331  Q2LA89  GNLFALRGSVELNGWDASLGGLYYGDKEKASTVVIEDQGNIGSLLAGEEIFYTTGSRLNG 332  NB3  GNFFALRGTVEVNGWDASLGGLYYGKKDKATVTTIEDQGNIGSLLAGEEIFYTRGSNLNG 332  Q2LAA9  GNFFALRGTVEVNGWDASLGGLYYGKKDKATVTTIEDQGNIGSLLAGEEIFYTRGSNLNG 333  B5QHE5  GNFFALRGTVEVNGWDASLGGLYYGKKDKITVTTIEDQGNLGSLLAGEEIFYTRGSNLNG 343  Q2LA96  GNFFALRGTVEVNGWDASLGGLYYGKKDKITVTTIEDQGNLGSLLAGEEIFYTRGSNLNG 343  Q2LAB4  GNFFALRGTVEVNGWDASLGGLYYGKKDKITVTTIEDQGNLGSLLAGEEIFYTRGSNLNG 343  Q2LA97  GNFFALRGTVEVNGWDASLGGLYYGKKDKVTVTTIEDQGNLGSLLAGEEIFYTRGSNLNG 343  Q2LAA7  GNFFALRGTVEVNGWDASLGGLYYGKKDKVTLTTIEDQGNLGSLLAGEEIFYTNGSNLNG 343  Q9F788  GNFFALRGTVEVNGWDASLGGLYYGKKDKVTLTTIEDQGNLGSLLAGEEIFYTNGSNLNG 343  Q2LA87  GNFFALRGTVEVNGWDASLGGLYYGKKDKVTLTTIEDQGNLGSLLAGEEIFYTNGSNLNG 343  Q2LA90  GNFFALRGTVEVNGWDATLGGLYYGDKDNLTVTTIEDQGNLGSLLAGEEIFYTRGSNLNG 343  Q2LAA3  GNFFALRGTVEVNGWDASLGGLYYGKKDKATVTTIEDQGNLGSLLAGQEIFYTRGSNLNG 344  Q0GF62  GNFFALRGTVEVNGWDASLGGLYYGKKDKFTVTTIEDQGNLGSLLAGEEIFYTHGSRLNG 342  **:***:* :*:*****:*******.*:: : . *:****:.*****:***** **.***                   (Arg 352)                      (Arg 381) Hb1  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB2  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 393  Q2LAB0  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Hb2  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  NB1  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q9F791  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Hb3  DTGRNIFGYVTGGYTFNEIVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  D3FNB0  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB1  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB8  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAA5  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB6  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LA95  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 391  P80672  (SEQ ID No. 1) DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAC5  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAANHLGGGKKLEAVARVDYKYSPKL 391  Q2LAA2  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB7  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB9  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LA91  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 391  NB2  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEDTA-HVGGGKKLEAVARVNYKYSPKL 390  Q2LA98  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEDTA-HVGGGKKLEAVARVDYKYSPKL 391  A3ZHA2  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q9F792  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAC0  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAS-HLGGGKKLEAVARVDYKYSPKL 391  QOGF63  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAS-HLGGGKKLEAVARVDYKYSPKL 390  Q2LAB3  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 383  Q2LA93  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAS-HLGGGKKLEAVARVDYKYSPKL 383  Q2LAA0  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAG-HLGGGKKLEAVARVDYKYSPKL 384  Q2LAC1  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 384  Q2LAC4  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 384  Q2LA94  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEATT-HLGGGKKLEAVARVDYKYSPKL 384  Q2LA92  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAVG-HLGGGKKLEAVARVDYKYSPKL 392  Q2LAA4  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTETAG-HLGGGKKLEAVARVDYKYSPKL 390  Q2LA89  DTGRNIFGYVTGGYTFNETVRVGADFVYGGTKTEAAN-HLGGGKKLEAVARVDYKYSPKL 391  NB3  DIGRNIFGYVTGGYTFNETVRVGADFVYGGTKTNIIG---GGGKKLEAVARVDYKYSPKL 389  Q2LAA9  DIGRNIFGYVTGGYTFNETVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 390  B5QHE5  DLGRNIFGYVTGGYTFNEAVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LA96  DLGRNIFGYVTGGYTFNEAVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LAB4  DLGRNIFGYVTGGYTFNEAVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LA97  DLGRNIFGYVTGGYTFNEAVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LAA7  DIGRNIFGYVTAGYTFNETVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q9F788  DIGRNIFGYVTAGYTFNETVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LA87  DIGRNIFGYVTAGYTFNETVRVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LA90  DLGRNIFGYVTGGYTFNEAVSVGADFVYGGTKTNIIG---QGGKKLEAVARVDYKYSPKL 400  Q2LAA3  DLGRNIFGYVTAGYTFNEAVAVGADFVYGGTKTGEIG---NGGKKLEAVARVDYKYSPKL 401  QOGF62  DAGRNIFGYVTGGYTFNETVRVGADFVYGGTKTENVG---EGGKKLEAVARVDYKYSPKL 399  * *********.****** **************        ***********:*******                        (Ser 397)  Hb1    NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB2 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    427  Q2LAB0 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Hb2    NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  NB1    NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q9F791 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Hb3    NFSAFYSYVNLDQGVNTNESADHXTVRLQALYKF                    424  D3FNB0 NFSAFY3YVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB1 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB8 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAA5 NFSAFY3YVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB6 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LA95 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    425  P80672  (SEQ ID No. 1)        NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAC5 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    425  Q2LAA2 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB7 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB9 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LA91 NFSAFYSYVNLDQGANTNESADHSTVRLQALYKF                    425  NB2    NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LA98 NFSAFYSYVNLDQGVNTNESADHSTVKLQALYKF                    425  A3ZHA2 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q9F792 NFSAFY3YVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAC0 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    425  QOGF63 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    424  Q2LAB3 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    417  Q2LA93 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    417  Q2LAA0 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    418  Q2LAC1 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    418  Q2LAC4 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    418  Q2LA94 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    418  Q2LA92 NFSAFYSYVNLDQGVNTNESADHSTVRLQALYKF                    426  Q2LAA4 NFSAFYSYVNLDEGVNTKESADHSTVRLQALYKF                    424  Q2LA89 NFSAFYSYVNLDEGVNTKESADHSTVRLQALYKF                    425  NB3    NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    420  Q2LAA9 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    421  B5QHE5 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LA96 NFSAFYSYVNVDT---DPESTHHDAVKLQALYKF                    431  Q2LAB4 NFSAFY3YVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LA97 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LAA7 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    431  Q9F788 NFSAFY3YVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LA87 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LA90 NFSAFYSYVNVDT---DPESTHHDAVRLQALYKF                    431  Q2LAA3 NFSAFY3YVNVDT---DPESTHHDAVRLQALYKF                    432  QOGF62 NFSAFYSYVNVDR---DPESTHHDAVRLQALYKF                    430         **********:*      **:.* :*:******* 

The major contributors in the interaction of glycosylated MOMP with Le^(b) are residues Arg^(352,381) and Lys²⁷⁸, whereas only residues 352 and 278 are involved in the interaction of non-glycosylated MOMP with Le^(b); FIG. 5 (paper). Residues Arg^(352,381) are conserved in all sequences examined, whilst residue Lys²⁷⁸ is semi-conserved and is replaced by Arg in some strains. The molecular properties of this amino acid suggests it would be able to mediate BgAg binding through hydrogen bond formation in a similar fashion to residues Arg^(352,381). 

1-29. (canceled)
 30. A composition comprising ferric quinate, complex of a 3,4-dihydroxyphenylalanine or tyrosine with Fe III or a compound with a structure selected from the group consisting of:

in an effective amount to reduce the number of Campylobacter present in the gastrointestinal tract of a human subject.
 31. The composition of claim 30, wherein the composition is a food supplement, drinking water or drinking water supplement.
 32. The composition of claim 30, wherein the compound is present in a concentration range between 34 to 340 μM.
 33. The composition of claim 30, wherein the compound specifically binds to at least one amino acid residue selected from the group consisting of Arg^(3S2), Thr²⁶⁸, Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵, Ile³³⁷, Arg³⁸¹, Asp²⁶¹, and Ser³⁹⁷ of MOMP (SEQ ID NO:1).
 34. The composition of claim 33, wherein the compound specifically binds to at least amino acid residue Thr²⁶⁸ of MOMP (SEQ ID NO.1).
 35. The composition of claim 30, wherein the compound reduces the campylobacter colony forming units in the gastrointestinal tract of the animal by at least 50%.
 36. The composition of claim 30, the Campylobacter is Campylobacter jejuni or Campylobacter coli.
 37. The composition of claim 30, wherein the compound is a complex of Fe III with 3,4-dihydroxyphenylalanine or tyrosine.
 38. The composition of claim 30, wherein the compound is ferric quinate.
 39. A method for treating or reducing Campylobacter colonization in a human subject comprising administering to the human the composition of claim
 1. 40. The method of claim 39, wherein the Campylobacter is Campylobacter jejuni or Campylobacter Coli.
 41. The method of claim 39, wherein the compound is administered orally.
 42. The method of claim 39, wherein the compound specifically binds to at least one amino acid residue selected from the group consisting of Arg^(3S2), Thr²⁶⁸, Lys²⁷⁸, Lys³⁸⁵, Asn²⁵⁸, Leu²⁹⁰, Tyr²⁹⁴, Phe³⁹⁵, Ile³³⁷, Arg³⁸¹, Asp²⁶¹, and Ser³⁹⁷ of MOMP (SEQ ID NO:1).
 43. The method of claim 39, wherein the compound specifically binds to at least amino acid residue Thr²⁶⁸ of MOMP (SEQ ID NO.1).
 44. The method of claim 39, wherein the compound reduces the campylobacter colony forming units in the gastrointestinal tract of the animal by at least 50%.
 45. The method of claim 39, wherein the compound is a complex of Fe III with 3,4-dihydroxyphenylalanine or tyrosine.
 46. The method of claim 39, wherein the compound is ferric quinate. 